Valve for preserving receptacles



June 19, 1928. 1,674,506

H. ERNST VALVE FOR PRESERVING RECEPTACLES Filed April 20, 1927 $1 11.13flaw W tions of these methods have also been em Patented June 19, 1 928.

UNI-TED STATES- nus matter, or BARMEN, GERMANY.

VALVE FOR PRESERVING RECEPTAGLES.

application filed April 20, 1927, Serial No.

This invention relates to the preservation of foods in cans or otherreceptacles, and relates more particularly to a valve to be used inconjunction with preserving receptacles which will permit excessivepressure within such a receptacle to be relieved while preventingingress of air, whereby the air may be evacuated from such receptacle.

It has long been known that the evacuation of air from a preservingreceptacle will improve,the keeping qualities of the food.

Bacteriologists recognize aerobic and nonaerobic bacteria, i. e., thosethat require air, or oxygen, for their development, and those thatthrive best when oxygen is excluded. Most putrefying bacteria are of theaerobic variety and require oxygen for their development. It has beendemonstrated by experiment that aerobic bacteria cease their vitalactivity after a relatively short time if they are deprived of air. Ingeneral, much more air is contained in preserving cans than is assumedto be the case. Thus, it has been ascertained. by experiment that about5 cu. in. of air escape from a tightly packed 35 oz. can of raw beefduring the first few minutes of heating. In the case of vegetables, from6 to 9 cu. in. of air have been driven off under similar conditions.

- The principle of canning, or preserving, is primarily the preventionof the growth of micro organisms. Various means have been employed forthis purpose, of which the commonest are sterilization by heat,refrigeration, and chemical agents or preservatives of various kinds.Suitable combinaployed.

Evacuation has been used to some extent in conjunction with heat,particularly'in the canning of ham and other meats, but this operationhas heretofore been not only expensive, but troublesome andtime-consuming, and has therefore been very little used. The usualprocesses of home canning have long been using' evacuation unconsciouslyby heating up the cans in boiling water with the cover loosely appliedover the usual rubber gasket, so that the water vapor formed in the cansexpels the air, the cans being tightly sealed before being removed fromthe heating bath. This evacuation is probably the best explanation ofthe fact that products of good keeping quality are commonly obtained,even with the employment of a sterilization temperature as low 185,219,and in Germany October 29, 1925.

as that of the boiling point of water. ,In support of this assertionthat evacuation of air .plays an important part in these homecanningprocesses, it may be noted that if one endeavors to sterilizehermetically sealed cans by the same heat treatment used in thesecanning processes, the products obtained are usually ,not of goodkeeping quality. U

It follows from the foregoing that it is possible to get along withlower sterilization temperatures and shorter sterilization periods-ifthe air is removed from the can. Moreover, thelower temperatures andshorter cooking periods have the decided advantage that they do notchange the consistency, flavor and color of the food being preserved asmuch as do the higher temperatures and long heating periods now incommon use. Furthermore, long continued heating of proteins at hightemperatures causes them to lose a large part of their I digestibilityandwholesomeness, and in addition is apt todestroy the vitamins, theimportance of which has been fully demonstrated by recent scientificresearch.

According to my invention I have pro vided a simple, inexpensive meansfor permitting the utilization ofthe principle of evacuating the airfrom a preserving receptacle in commercial practice. My inventionattains not only the advantages pointed out above, but other advantageswhich will be apparent from the following i'nore detailed description.

In the accompanying drawings, which form a part of this specification,and in which like reference characters denote like parts throughout theseveral views thereof: Figure 1 is a top plan view of a reserving canhaving my invention applied t ereto;

Figure 2 is a dissembled view of the parts comprising my valve; and

Figure 3 is a central vertical section through a valve according to myinvention aflixed to a can.

Referring more particularly to the drawings, 10 designates a preservingcan of the usual construction, having a top 11, to which is secured myimproved valve, denoted generally by the numeral 12. In the specificmodification of my invention described and illustrated by way ofexample, the valve is intended to be affixed to the can top during themanufacture of the can' and before the same is filled and sealed in theusual manner.

The valve may obviously be used in connection with either glass or metalpreserving receptacles. Of course its most general use is in connectionwith the ordinary type of metal preserving can in common commercial use.I

The valve itself comprises a bottom member 13, a top member 14, and agasket or washer placed therebetween. The members 13 and 14 arepreferably made of sheet metal and may be stamped to the desired shapein large quantities and very economically by the use of the usual andwell-known die-stamping machines. The washer 15 is preferably of softrubber but other suitable material could be substituted.

Member 13 may conveniently be formed 7 with" a peripheral flange 16,inclined a little outwardly from the vertical, surrounding a rim 17which preferably slopes in a slightly downwards direction towards thecenter of member 1?;i as shown in the drawings. An

upwardly ished intermediate portion 18, an adjoining dome-like section19, and a central knob 20 surmounting dome 19, complete the member 13.

The upper member 14 is provided with a rim 21 which follows theinclination of the rim 17 of member13, and with an upwardly inclinedintermediate portion 22 which is substantially parallel totheinclination of the portion 18. The central portion 23 of I member 14may be horizontal and is provided with an a erture 24, through whichknob 20 is inten ed to extend.

The top of the can with which my valve 12 is to be used is provided withan apertured depression having a side wall 25 and a rim 26, theconformation of which correspond respectively 'to the conformation ofthe portions 16 and 17 of the member 13. The member 13 is placedbeneaththis depression as shown in Figure 3. The washer 15 is then'placed abovethe rim 25 of the recess in the top of the can, and the member 14 placedon top of the washer. The valve is then fastened together by strikingthe knob 20 with a suitable punch or drift, thereby flattening out theknob as shown in Figure 3 and clamping the various parts of the valvemore or less tightly together,

and to the top of the can. It will be observed that the various parts ofthe valve 12 are so proportioned that the horizontal central portion 23of member 14 is about the same plane as the junction between knob 20 anddome 19 of member 13.

After the can has been filled with the food to be preserved, and sealedin the usual manner, it is then subjected to the usual process ofsterilizing by heating, with the exception that, as above stated, thetemperature used may be lower and the duration of the heating may beshorter. During this heating the air in the can will expand, and, if therim 26 of the recess, through the central aperture of the washer 15, andout through the aperture 24 around the edge of the flattened knob 20. It'will be noted that the joints betwen the member 13 and the edges 25 and26 of the recess, and between the fiattened knob 20 and the top member14, are not intended to be made absolutely tight by the mere operationof clinching the parts of 4 the valve together.

When the heating of the can is completed the resulting drop intemperature causes a lowering of the pressure within the can, but myvalve is so constructed that it will not permit air to enter even thoughpressure outside of the can exceed that within, for the reason that anyexcess of pressure outside of the can will cause the rubber gasket 15 tobecome flattened against the portion 18 of the lower member 13, and thusto effectually seal the joint between the rim 26 and the member 13. Inother words, the rupber gasket 15 acts very much as a flap va ve.

It is apparent that my valve is well,

adapted to large-scale canning industries. The manner of filling and;sealing the preserving cans is not changed, but may be effected in thewell-known manner and with the machines .hitherto in use. The valve doesnot project from the cover of the can to any great extent, either fromthe inside or toward the outside, and hence is not 'in the way. Thediameter of the valve is only 6/10ths of an inch in its preferred form,and the depth is only 1/10 inch. The valve has no visible opening on theoutside, which prevents interference by curiousv persons, and also hasno unprotected opening on the inside, thereby preventing contact of thesealing washer with thecontents of the can. Furthermore, theconstruction of the valve is such that it cannot be damaged by roughhandling of the can, and it is absolutely positive in its operation. Theconstruction is so simple that it increases the cost of the preservingcan but.very little, and the economies effected by the shortening of theheating operation and the improved quality of the food being preserved,more than compensate for this additional expense. Furthermore, theoperation of my valve presents a great advantage over evacuationprocesses as formerly used in that previously the cans were evacuatedbefore sterilizing and any gases developing during cooking perforceremained in the can, whereas with my valve they are permitted to escape.In preserving many classes of food this is of. the greatest importancesince these gases frequently have an injurious eifect on the walls ofthe cans.

It might be supposed that the contents of the can would be permitted toboil dry during sterilization by the operation of the valve. This,however, is not the case because there must be a considerable excess ofpressure within the can over atmospheric in order to open the valve, andthis excess pressure of course represents water vapor which will beretained upon cooking.

Other advantages of my improi ed valve are that it is no longernecessary to fill the can to the top with fat or gravy in canning friedfoods, as was formerly necessary. This results in a great saving of fatand also improves the flavor of the food and preserves its character asa fried canned. food rather than making it resemble a food boiled in fator gravy.

Other advantages and applications of my improved can valve will beapparent to those skilled in the art of preserving foods, and it will beobvious that many changes or modifications might be made withoutaflecting the spirit of my invention.

I desire to be limited therefore only by the prior art and scope of theappended claims.

I claim:

1. In combination with a receptacle forpreserving foods, a valvecomprising a valve seat, a flexlble sealing member seated there on andhavlng a .central aperture, a cover disposed on said sealing member andlocated outside of said receptacle, said cover being spaced from thecentral portion of said sealing member to permit displacement thereof byexcessive pressure within said receptacle, and means including aprojection on said valve seat extending through the aperture of saidsealing member for securing said cover to said seat and for clamping theperiphery of said sea-ling member therebetween, the joint between saidprojection and said cover being located outside of said receptacle andbeyond the valve.

2. In combination with a receptacle for preserving foods, a valvecomprising a metallic valve seat, a flexible sealing member seatedthereon and. having a central aperture, a cover disposed on said sealingmember and located outside of said receptacle, said cover being spaced.from the central portion of said sealing member to permit displacementthereof by excessive pressure within said receptacle, an integral riveton said seat extending through the aperture of said sealing member, anda head on said rivet for securing saidcover to said seat and forclamping the periphery of said sealing member therebetween, said headbeing 10- 3. In combination with a receptacle for preserving foods, avalve comprising a metallic valve seat, a flexible sealing member seatedthereon and having a central aperture, a cover disposed on said sealingmember and located outside of said receptacle, said cover being spacedfrom the central portion of said sealing member to permit displacementthereof by excessive pressure within said receptacle, an integral hollowrivet formed on said seat extending through the aperture of said sealingmember, said seat having a" conical raised portionsurrounding saidhollow rivet to press said scaling member upward and increase itspressure against said seat, and a head on said rivet for securing saidcover to said seat and for clamping the periphery of said sealing membertherebetween, said head being located outside of said receptacle andbeyond the valve.

4:.In combination with a receptacle for preserving foods having anaperture in a Wall thereof, a valve adapted to close said apertureagainst ingress of air comprising a lower member seated against theinner side of said wall, a flexible sealing member having an apertureregistering with the aperture in said wall and seated upon the outerside of said wall, an upper member seated upon said flexible sealingmember and spaced therefrom adjacent the aperture thereof, and meanspassing through said registering apertures for clamping the pe ripheryof said sealing member between said can Wall and said upper member whilepermitting displacementof the central portion of said sealing memberfrom its seat against said lower member by excessive pressure withinvthe receptacle the joint between said means and said upper member beinglocated outside of said receptacle and beyond said sealing member. I

5. In combination with a receptacle for preserving foods having anaperture in a wall thereof, a-valve adapted to close saidapertureagainst ingress of air, comprising a lower member seated againstthe inner tral portion of said sealing member from its seat against saidlower member by excessive pressure Within the receptacle, the jointbetween said projecting portion and said upper member being locatedoutside of said receptacle and beyond said sealing member.

6. In combination with a receptacle for preserving foods having anaperture in a wall thereof, a valve adapted to close said apertureagainst ingress of air, comprising a metallic valve seat seated againstthe inner side of said wall and having an integral centrally locatedhollow rivet projecting through said aperture, a flexible sealing membersurrounding said hollow rivet and seated upon the outer side of saidwall a metallic cover also surrounding said hollow rivet and having itsperiphery seated upon the periphery of said sealing member, theintermediate portion of said cover being spaced from said sealingmember, and a head formed on said hollow rivet adapted to clamp theperiphery of saidsealing mem- HANS ERNST.

